This invention relates to a process for analyzing anions, and particularly to a process for analyzing anions suitable for analyzing anions having a low degree of dissociation and a low electroconductivity such as borate ion and carbonate ion with high precision.
Recently, techniques of microanalysis of liquid waste have been advanced, and components on a ppm level can be analyzed in a short time with good precision. Particularly, the ion chromatography apparatus based on U.S. Pat. No. 3,897,213 can perform simultaneous analysis of many components on a pmm level within 30 minutes by separating cations such as sodium ion, potassium ion, etc., or anions such as chloride ion, nitrate ion, sulfate ion, etc. from one another by means of ion exchange resin and neutralizing an eluate with another kind of ion exchange resin, thereby leading only the desired kinds of ions to an electroconductivity type detector. However, it has been found as a result of studies made by the present inventors that the process of said U.S. Pat. No. 3,897,213 has such drawbacks that, since an electroconductivity type detector is used for detection, the ions having a high electroconductivity in an aqueous solution can be measured with a high sensitivity, but carbonate ion, or borate ion having a low degree of dissociation, that is, a low electroconductivity, has such a low sensitivity that it cannot be throughly analyzed.